Semiconductor Device and Method of Forming Low Profile Fan-Out Package with Vertical Interconnection Units

ABSTRACT

A semiconductor device includes a semiconductor die. A first interconnect structure is disposed over a peripheral region of the semiconductor die. A semiconductor component is disposed over the semiconductor die. The semiconductor component includes a second interconnect structure. The semiconductor component is disposed over the semiconductor die to align the second interconnect structure with the first interconnect structure. The first interconnect structure includes a plurality of interconnection units disposed around first and second adjacent sides of the semiconductor die to form an L-shape border of the interconnection units around the semiconductor die. A third interconnect structure is formed over the semiconductor die perpendicular to the first interconnect structure. An insulating layer is formed over the semiconductor die and first interconnect structure. A plurality of vias is formed through the insulating layer and into the first interconnect structure with the second interconnect structure disposed within the vias.

CLAIM TO DOMESTIC PRIORITY

The present application is a continuation of U.S. patent applicationSer. No. 14/038,575, filed Sep. 26, 2013, which claims the benefit ofU.S. Provisional Application No. 61/735,926, filed Dec. 11, 2012, whichapplications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates in general to semiconductor devices and,more particularly, to a semiconductor device and method of forming afan-out package or package-on-package semiconductor device with verticalinterconnection units.

BACKGROUND OF THE INVENTION

Semiconductor devices are commonly found in modern electronic products.Semiconductor devices vary in the number and density of electricalcomponents. Discrete semiconductor devices generally contain one type ofelectrical component, e.g., light emitting diode (LED), small signaltransistor, resistor, capacitor, inductor, and power metal oxidesemiconductor field effect transistor (MOSFET). Integrated semiconductordevices typically contain hundreds to millions of electrical components.Examples of integrated semiconductor devices include microcontrollers,microprocessors, charged-coupled devices (CCDs), solar cells, anddigital micro-mirror devices (DMDs).

Semiconductor devices perform a wide range of functions such as signalprocessing, high-speed calculations, transmitting and receivingelectromagnetic signals, controlling electronic devices, transformingsunlight to electricity, and creating visual projections for televisiondisplays. Semiconductor devices are found in the fields ofentertainment, communications, power conversion, networks, computers,and consumer products. Semiconductor devices are also found in militaryapplications, aviation, automotive, industrial controllers, and officeequipment.

Semiconductor devices exploit the electrical properties of semiconductormaterials. The structure of semiconductor material allows its electricalconductivity to be manipulated by the application of an electric fieldor base current or through the process of doping. Doping introducesimpurities into the semiconductor material to manipulate and control theconductivity of the semiconductor device.

A semiconductor device contains active and passive electricalstructures. Active structures, including bipolar and field effecttransistors, control the flow of electrical current. By varying levelsof doping and application of an electric field or base current, thetransistor either promotes or restricts the flow of electrical current.Passive structures, including resistors, capacitors, and inductors,create a relationship between voltage and current necessary to perform avariety of electrical functions. The passive and active structures areelectrically connected to form circuits, which enable the semiconductordevice to perform high-speed operations and other useful functions.

Semiconductor devices are generally manufactured using two complexmanufacturing processes, i.e., front-end manufacturing, and back-endmanufacturing, each involving potentially hundreds of steps. Front-endmanufacturing involves the formation of a plurality of die on thesurface of a semiconductor wafer. Each semiconductor die is typicallyidentical and contains circuits formed by electrically connecting activeand passive components. Back-end manufacturing involves singulatingindividual semiconductor die from the finished wafer and packaging thedie to provide structural support and environmental isolation. The term“semiconductor die” as used herein refers to both the singular andplural form of the words, and accordingly, can refer to both a singlesemiconductor device and multiple semiconductor devices.

One goal of semiconductor manufacturing is to produce smallersemiconductor devices. Smaller devices typically consume less power,have higher performance, and can be produced more efficiently. Inaddition, smaller semiconductor devices have a smaller footprint, whichis desirable for smaller end products. A smaller semiconductor die sizecan be achieved by improvements in the front-end process resulting insemiconductor die with smaller, higher density active and passivecomponents. Back-end processes may result in semiconductor devicepackages with a smaller footprint by improvements in electricalinterconnection and packaging materials.

A reduced package profile is of particular importance for packaging inthe cellular or smart phone industry. The electrical interconnectionbetween three dimensional (3D) fan-out semiconductor packages andexternal devices utilize various interconnect types, such as throughsilicon vias (TSVs) and through hole vias (THVs) interconnect byredistribution layers (RDLs). RDLs serve as intermediate layers forelectrical interconnect within a package including electricalinterconnect with package input/output (I/O) pads which provideelectrical connection from a semiconductor die within a semiconductorpackage to points external to the semiconductor package. RDLs can beformed over both a front surface and back surface of the semiconductordie within the semiconductor package and with a thin wafer and panelhandling capability. However, the formation of multiple RDLs over afront surface and back surface of the semiconductor die can requiretemporary bonding with customized bonding material, which can requirehigher temperature resistance, and can be a slow and costly approach formaking electrical interconnection for the semiconductor packageresulting in higher fabrication costs. Additionally, thin stacks of RDLsinclude structural limitations and reduced design flexibility. Forexample, RDLs provide limited mechanical strength for package processingand reliability. RDLs lack modularity and are difficult to form inspecific areas of the semiconductor package.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a printed circuit board (PCB) with different types ofpackages mounted to its surface;

FIGS. 2a-2c illustrate further detail of the representativesemiconductor packages mounted to the PCB;

FIGS. 3a-3c illustrate a semiconductor wafer with a plurality ofsemiconductor die separated by saw streets;

FIGS. 4a-4n illustrate a process of forming a low profile fan-outpackage-on-package structure with 3D vertical interconnection units;

FIG. 5 illustrates a robust semiconductor package with interconnectionunits;

FIGS. 6a-6h illustrate another semiconductor package withinterconnection units disposed over opposing surfaces of a semiconductordie and support structures;

FIG. 7 illustrates an alternative embodiment of a semiconductor packagewith LGA pads; and

FIGS. 8a-8g illustrate another semiconductor package with RDL formedbetween semiconductor packages and a back surface protection layer.

DETAILED DESCRIPTION OF THE DRAWINGS

The present invention is described in one or more embodiments in thefollowing description with reference to the figures, in which likenumerals represent the same or similar elements. While the invention isdescribed in terms of the best mode for achieving the invention'sobjectives, it will be appreciated by those skilled in the art that itis intended to cover alternatives, modifications, and equivalents as maybe included within the spirit and scope of the invention as defined bythe appended claims and their equivalents as supported by the followingdisclosure and drawings.

Semiconductor devices are generally manufactured using two complexmanufacturing processes: front-end manufacturing and back-endmanufacturing. Front-end manufacturing involves the formation of aplurality of die on the surface of a semiconductor wafer. Each die onthe wafer contains active and passive electrical components, which areelectrically connected to form functional electrical circuits. Activeelectrical components, such as transistors and diodes, have the abilityto control the flow of electrical current. Passive electricalcomponents, such as capacitors, inductors, and resistors, create arelationship between voltage and current necessary to perform electricalcircuit functions.

Passive and active components are formed over the surface of thesemiconductor wafer by a series of process steps including doping,deposition, photolithography, etching, and planarization. Dopingintroduces impurities into the semiconductor material by techniques suchas ion implantation or thermal diffusion. The doping process modifiesthe electrical conductivity of semiconductor material in active devicesby dynamically changing the semiconductor material conductivity inresponse to an electric field or base current. Transistors containregions of varying types and degrees of doping arranged as necessary toenable the transistor to promote or restrict the flow of electricalcurrent upon the application of the electric field or base current.

Active and passive components are formed by layers of materials withdifferent electrical properties. The layers can be formed by a varietyof deposition techniques determined in part by the type of materialbeing deposited. For example, thin film deposition can involve chemicalvapor deposition (CVD), physical vapor deposition (PVD), electrolyticplating, and electroless plating processes. Each layer is generallypatterned to form portions of active components, passive components, orelectrical connections between components.

Back-end manufacturing refers to cutting or singulating the finishedwafer into the individual semiconductor die and then packaging thesemiconductor die for structural support and environmental isolation. Tosingulate the semiconductor die, the wafer is scored and broken alongnon-functional regions of the wafer called saw streets or scribes. Thewafer is singulated using a laser cutting tool or saw blade. Aftersingulation, the individual semiconductor die are mounted to a packagesubstrate that includes pins or contact pads for interconnection withother system components. Contact pads formed over the semiconductor dieare then connected to contact pads within the package. The electricalconnections can be made with solder bumps, stud bumps, conductive paste,or wirebonds. An encapsulant or other molding material is deposited overthe package to provide physical support and electrical isolation. Thefinished package is then inserted into an electrical system and thefunctionality of the semiconductor device is made available to the othersystem components.

FIG. 1 illustrates electronic device 50 having a chip carrier substrateor printed circuit board (PCB) 52 with a plurality of semiconductorpackages mounted on its surface. Electronic device 50 can have one typeof semiconductor package, or multiple types of semiconductor packages,depending on the application. The different types of semiconductorpackages are shown in FIG. 1 for purposes of illustration.

Electronic device 50 can be a stand-alone system that uses thesemiconductor packages to perform one or more electrical functions.Alternatively, electronic device 50 can be a subcomponent of a largersystem. For example, electronic device 50 can be part of a cellularphone, personal digital assistant (PDA), digital video camera (DVC), orother electronic communication device. Alternatively, electronic device50 can be a graphics card, network interface card, or other signalprocessing card that can be inserted into a computer. The semiconductorpackage can include microprocessors, memories, application specificintegrated circuits (ASIC), logic circuits, analog circuits, radiofrequency (RF) circuits, discrete devices, or other semiconductor die orelectrical components. Miniaturization and weight reduction areessential for the products to be accepted by the market. The distancebetween semiconductor devices may be decreased to achieve higherdensity.

In FIG. 1, PCB 52 provides a general substrate for structural supportand electrical interconnect of the semiconductor packages mounted on thePCB. Conductive signal traces 54 are formed over a surface or withinlayers of PCB 52 using evaporation, electrolytic plating, electrolessplating, screen printing, or other suitable metal deposition process.Signal traces 54 provide for electrical communication between each ofthe semiconductor packages, mounted components, and other externalsystem components. Traces 54 also provide power and ground connectionsto each of the semiconductor packages.

In some embodiments, a semiconductor device has two packaging levels.First level packaging is a technique for mechanically and electricallyattaching the semiconductor die to an intermediate carrier. Second levelpackaging involves mechanically and electrically attaching theintermediate carrier to the PCB. In other embodiments, a semiconductordevice may only have the first level packaging where the die ismechanically and electrically mounted directly to the PCB.

For the purpose of illustration, several types of first level packaging,including bond wire package 56 and flipchip 58, are shown on PCB 52.Additionally, several types of second level packaging, including ballgrid array (BGA) 60, bump chip carrier (BCC) 62, dual in-line package(DIP) 64, land grid array (LGA) 66, multi-chip module (MCM) 68, quadflat non-leaded package (QFN) 70, and quad flat package 72, are shownmounted on PCB 52. Depending upon the system requirements, anycombination of semiconductor packages, configured with any combinationof first and second level packaging styles, as well as other electroniccomponents, can be connected to PCB 52. In some embodiments, electronicdevice 50 includes a single attached semiconductor package, while otherembodiments call for multiple interconnected packages. By combining oneor more semiconductor packages over a single substrate, manufacturerscan incorporate pre-made components into electronic devices and systems.Because the semiconductor packages include sophisticated functionality,electronic devices can be manufactured using less expensive componentsand a streamlined manufacturing process. The resulting devices are lesslikely to fail and less expensive to manufacture resulting in a lowercost for consumers.

FIGS. 2a-2c show exemplary semiconductor packages. FIG. 2a illustratesfurther detail of DIP 64 mounted on PCB 52. Semiconductor die 74includes an active region containing analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed within the die and are electricallyinterconnected according to the electrical design of the die. Forexample, the circuit can include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements formedwithin the active region of semiconductor die 74. Contact pads 76 areone or more layers of conductive material, such as aluminum (Al), copper(Cu), tin (Sn), nickel (Ni), gold (Au), or silver (Ag), and areelectrically connected to the circuit elements formed withinsemiconductor die 74. During assembly of DIP 64, semiconductor die 74 ismounted to an intermediate carrier 78 using a gold-silicon eutecticlayer or adhesive material such as thermal epoxy or epoxy resin. Thepackage body includes an insulative packaging material such as polymeror ceramic. Conductor leads 80 and bond wires 82 provide electricalinterconnect between semiconductor die 74 and PCB 52. Encapsulant 84 isdeposited over the package for environmental protection by preventingmoisture and particles from entering the package and contaminatingsemiconductor die 74 or bond wires 82.

FIG. 2b illustrates further detail of BCC 62 mounted on PCB 52.Semiconductor die 88 is mounted over carrier 90 using an underfill orepoxy-resin adhesive material 92. Bond wires 94 provide first levelpackaging interconnect between contact pads 96 and 98. Molding compoundor encapsulant 100 is deposited over semiconductor die 88 and bond wires94 to provide physical support and electrical isolation for the device.Contact pads 102 are formed over a surface of PCB 52 using a suitablemetal deposition process such as electrolytic plating or electrolessplating to prevent oxidation. Contact pads 102 are electricallyconnected to one or more conductive signal traces 54 in PCB 52. Bumps104 are formed between contact pads 98 of BCC 62 and contact pads 102 ofPCB 52.

In FIG. 2c , semiconductor die 58 is mounted face down to intermediatecarrier 106 with a flipchip style first level packaging. Active region108 of semiconductor die 58 contains analog or digital circuitsimplemented as active devices, passive devices, conductive layers, anddielectric layers formed according to the electrical design of the die.For example, the circuit can include one or more transistors, diodes,inductors, capacitors, resistors, and other circuit elements withinactive region 108. Semiconductor die 58 is electrically and mechanicallyconnected to carrier 106 through bumps 110.

BGA 60 is electrically and mechanically connected to PCB 52 with a BGAstyle second level packaging using bumps 112. Semiconductor die 58 iselectrically connected to conductive signal traces 54 in PCB 52 throughbumps 110, signal lines 114, and bumps 112. A molding compound orencapsulant 116 is deposited over semiconductor die 58 and carrier 106to provide physical support and electrical isolation for the device. Theflipchip semiconductor device provides a short electrical conductionpath from the active devices on semiconductor die 58 to conductiontracks on PCB 52 in order to reduce signal propagation distance, lowercapacitance, and improve overall circuit performance. In anotherembodiment, the semiconductor die 58 can be mechanically andelectrically connected directly to PCB 52 using flipchip style firstlevel packaging without intermediate carrier 106.

FIG. 3a shows a semiconductor wafer 120 with a base substrate material122, such as silicon, germanium, gallium arsenide, indium phosphide, orsilicon carbide, for structural support. A plurality of semiconductordie or components 124 is formed on wafer 120 separated by a non-active,inter-die wafer area or saw street 126 as described above. Saw street126 provides cutting areas to singulate semiconductor wafer 120 intoindividual semiconductor die 124.

FIG. 3b shows a cross-sectional view of a portion of semiconductor wafer120. Each semiconductor die 124 has a back or non-active surface 128 andactive surface 130 containing analog or digital circuits implemented asactive devices, passive devices, conductive layers, and dielectriclayers formed within the die and electrically interconnected accordingto the electrical design and function of the die. For example, thecircuit may include one or more transistors, diodes, and other circuitelements formed within active surface 130 to implement analog circuitsor digital circuits, such as digital signal processor (DSP), ASIC,memory, or other signal processing circuit. Semiconductor die 124 mayalso contain integrated passive devices (IPDs), such as inductors,capacitors, and resistors, for RF signal processing.

An electrically conductive layer 132 is formed over active surface 130using PVD, CVD, electrolytic plating, electroless plating process, orother suitable metal deposition process. Conductive layer 132 can be oneor more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electricallyconductive material. Conductive layer 132 operates as contact padselectrically connected to the circuits on active surface 130. Conductivelayer 132 can be formed as contact pads disposed side-by-side a firstdistance from the edge of semiconductor die 124, as shown in FIG. 3b .Alternatively, conductive layer 132 can be formed as contact pads thatare offset in multiple rows such that a first row of contact pads isdisposed a first distance from the edge of the die, and a second row ofcontact pads alternating with the first row is disposed a seconddistance from the edge of the die.

An optional insulating or passivation layer 134 is formed over activesurface 130 using PVD, CVD, screen printing, spin coating, spraycoating, sintering or thermal oxidation. The insulating layer 134contains one or more layers of silicon dioxide (SiO2), silicon nitride(Si3N4), silicon oxynitride (SiON), tantalum pentoxide (Ta2O5), aluminumoxide (Al2O3), or other material having similar insulating andstructural properties. The insulating layer 134 covers and providesprotection for active surface 130. A portion of insulating layer 134 isremoved by an etching process or by laser direct ablation (LDA) usinglaser 135 to form openings 136 which expose conductive layer 132 andprovide for subsequent electrical interconnect.

Semiconductor wafer 120 undergoes electrical testing and inspection aspart of a quality control process. Manual visual inspection andautomated optical systems are used to perform inspections onsemiconductor wafer 120. Software can be used in the automated opticalanalysis of semiconductor wafer 120. Visual inspection methods mayemploy equipment such as a scanning electron microscope, high-intensityor ultra-violet light, or metallurgical microscope. Semiconductor wafer120 is inspected for structural characteristics including warpage,thickness variation, surface particulates, irregularities, cracks,delamination, and discoloration.

The active and passive components within semiconductor die 124 undergotesting at the wafer level for electrical performance and circuitfunction. Each semiconductor die 124 is tested for functionality andelectrical parameters using a probe or other testing device. A probe isused to make electrical contact with nodes or contact pads 132 on eachsemiconductor die 124 and provides electrical stimuli to the contactpads. Semiconductor die 124 responds to the electrical stimuli, which ismeasured and compared to an expected response to test functionality ofthe semiconductor die. The electrical tests may include circuitfunctionality, lead integrity, resistivity, continuity, reliability,junction depth, electro-static discharge (ESD), radio frequency (RF)performance, drive current, threshold current, leakage current, andoperational parameters specific to the component type. The inspectionand electrical testing of semiconductor wafer 120 enables semiconductordie 124 that pass to be designated as known good die (KGD) for use in asemiconductor package.

In FIG. 3c , semiconductor wafer 120 is singulated through saw street126 using a saw blade or laser cutting tool 138 into individualsemiconductor die 124. The individual semiconductor die 124 can beinspected and electrically tested for identification of KGD postsingulation.

FIGS. 4a-4n illustrate, in relation to FIGS. 1 and 2 a-2 c, a process offorming a low profile 3D semiconductor package structure usingprefabricated modular interconnection units. FIG. 4a shows across-sectional view of a portion of a carrier or temporary substrate140 containing sacrificial base material such as silicon, polymer,beryllium oxide, glass, or other suitable low-cost, rigid material forstructural support. An interface layer or double-sided tape 142 isformed over carrier 140 as a temporary adhesive bonding film, etch-stoplayer, or thermal release layer.

Carrier 140 can be a round or rectangular panel (greater than 300 mm)with capacity for multiple semiconductor die 124. Carrier 140 may have alarger surface area than the surface area of semiconductor wafer 120. Alarger carrier reduces the manufacturing cost of the semiconductorpackage as more semiconductor die can be processed on the larger carrierthereby reducing the cost per unit. Semiconductor packaging andprocessing equipment are designed and configured for the size of thewafer or carrier being processed.

To further reduce manufacturing costs, the size of carrier 140 isselected independent of the size of semiconductor die 124 or size ofsemiconductor wafer 120. That is, carrier 140 has a fixed orstandardized size, which can accommodate various size semiconductor die124 singulated from one or more semiconductor wafers 120. In oneembodiment, carrier 140 is circular with a diameter of 330 mm. Inanother embodiment, carrier 140 is rectangular with a width of 560 mmand length of 600 mm. Semiconductor die 124 may have dimensions of 10 mmby 10 mm, which are placed on the standardized carrier 140.Alternatively, semiconductor die 124 may have dimensions of 20 mm by 20mm, which are placed on the same standardized carrier 140. Accordingly,standardized carrier 140 can handle any size semiconductor die 124,which allows subsequent semiconductor processing equipment to bestandardized to a common carrier, i.e., independent of die size orincoming wafer size. Semiconductor packaging equipment can be designedand configured for a standard carrier using a common set of processingtools, equipment, and bill of materials to process any semiconductor diesize from any incoming wafer size. The common or standardized carrier140 lowers manufacturing costs and capital risk by reducing oreliminating the need for specialized semiconductor processing linesbased on die size or incoming wafer size. By selecting a predeterminedcarrier size to use for any size semiconductor die from allsemiconductor wafer, a flexible manufacturing line can be implemented.

In FIG. 4b , semiconductor die 124 from FIG. 3c are mounted to dieattach area 150 of carrier 140 using, for example, a pick and placeoperation with active surface 130 oriented toward the carrier. Thesemiconductor die 124 mounted to die attach area 150 may be chosen fromKGD. Semiconductor die 124 are pressed into interface layer 142 suchthat a portion of insulating layer 134 is disposed within and surroundedby the interface layer.

FIG. 4b also shows pre-fabricating modular 3D interconnection units 600including core substrate 572 with a plurality of through conductive vias574-575 is formed through the core substrate. An electrically conductivelayer or RDL 576 is formed over core substrate 572 and conductive vias574-575 using a patterning and metal deposition process such asprinting, PVD, CVD, sputtering, electrolytic plating, and electrolessplating. Conductive layer 576 includes one or more layers of Al, Cu, Sn,Ni, Au, Ag, or other suitable electrically conductive material.Conductive layer 576 is electrically connected to conductive vias574-575.

An insulating or passivation layer 578 is formed over core substrate 572and conductive layer 576 using PVD, CVD, printing, spin coating, spraycoating, slit coating, rolling coating, lamination, sintering or thermaloxidation. Insulating layer 578 includes one or more layers of SiO2,Si3N4, SiON, Ta2O5, Al2O3, HfO2, BCB, PI, PBO, polymer dielectric resistwith or without fillers or fibers, or other material having similarstructural and dielectric properties. A portion of insulating layer 578is removed by LDA, etching, or other suitable process to expose portionsof conductive layer 576 over conductive vias 574.

An insulating or passivation layer 582 is formed over core substrate 572using PVD, CVD, printing, spin coating, spray coating, slit coating,rolling coating, lamination, sintering or thermal oxidation. Theinsulating layer 582 includes one or more layers of SiO2, Si3N4, SiON,Ta2O5, Al2O3, HfO2, BCB, PI, PBO, polymer dielectric resist with orwithout fillers or fibers, or other material having similar structuraland dielectric properties. A portion of insulation layer 582 is removedby LDA or etching to expose portions of conductive vias 574-575.

An electrically conductive layer or RDL 580 is formed over coresubstrate 572 and conductive vias 574 opposite conductive layer 576using a patterning and metal deposition process such as printing, PVD,CVD, sputtering, electrolytic plating, and electroless plating.Conductive layer 580 includes one or more layers of Al, Cu, Sn, Ni, Au,Ag, Ti, W, or other suitable electrically conductive material.Conductive layer 580 is electrically connected to conductive vias 574.Alternatively, conductive vias 574 are formed through core substrate 572after forming conductive layer 576 and conductive layer 580.

Modular interconnection units 600 are mounted to carrier 140 using, forexample, a pick and place operation with an optional adhesive.Interconnection units 600 are disposed on interface layer 142 in aperipheral region of semiconductor die 124. Interconnection units 600are disposed in an L-shaped arrangement over carrier 140 around a cornerof die attach area 150 and at least partially along a length of twosides of semiconductor die 124, as shown in FIG. 4c . Interconnectionunits 600 may be clustered together to form a continuous layer ofinterconnection units, or disposed over isolated and predeterminedportions over carrier 140. In some embodiments, semiconductor die 124 ismounted to carrier 140 before mounting interconnection units 600.Alternatively, interconnection units 600 are mounted to carrier 140before mounting semiconductor die 124. Semiconductor die 124 andinterconnection units 600 can be simultaneously mounted to carrier 140.

Interconnection units 600 are a modular vertical interconnect componentthat are easily disposed within a semiconductor package to form aborder, slot, or frame over or around a side portion of semiconductordie 124. Modular interconnection units 600 are disposed aroundsemiconductor die 124 to provide vertical interconnect while reducingthe number or quantity of RDLs formed within the semiconductor package.For example, interconnection units 600 provide partial backside RDL withimproved efficiency during manufacturing steps. Interconnection units600 disposed around semiconductor die 124 also provide structuralsupport during packaging and reduce shifting during the application ofencapsulant and additional semiconductor components. Interconnectionunits 600 extend design flexibility and reduce z-direction packageheight while providing valuable vertical interconnect. As individualmodular units, interconnection units 600 are disposed within thesemiconductor package at specific predetermined locations aroundsemiconductor die 124 to optimize the space within the semiconductorpackage. Using interconnection units 600 reduces manufacturing steps,and greatly increases flexibility of semiconductor package design.

In some embodiments, interconnection units 600 have a height greaterthan a height or thickness of semiconductor die 124. In otherembodiments, interconnection units 600 have a height equal to or lessthan a height or thickness of the semiconductor die. When mountinginterconnection units adjacent to semiconductor die 124, a gap or space152 may remain around die attach area 150 between die attach area 150and interconnection units 600. Alternatively, die attach area 150 isallocated such that semiconductor die 124 abut or contactinterconnection units 600.

FIG. 4d shows composite substrate or reconstituted wafer 170 withencapsulant 160 deposited over semiconductor die 124 and interconnectionunits 600. Reconstituted wafer 170 can be processed into many types ofsemiconductor packages, including three dimensional (3D) packages, suchas package-on-package (PoP), embedded wafer level ball grid array(eWLB), fan-in wafer level chip scale packages (WLCSP), reconstituted orembedded wafer level chip scale packages (eWLCSP), fan-out WLCSP,flipchip packages, or other semiconductor packages. Reconstituted wafer170 is configured according to the specifications of the resultingsemiconductor package. The distance between semiconductor die 124 oncarrier 140 is optimized for manufacturing the semiconductor packages atthe lowest unit cost. The larger surface area of carrier 140accommodates more semiconductor die 124 and lowers manufacturing cost asmore semiconductor die 124 are processed per reconstituted wafer 170.The number of semiconductor die 124 mounted to carrier 140 can begreater than the number of semiconductor die 124 singulated fromsemiconductor wafer 120. Carrier 140 and reconstituted wafer 170 providethe flexibility to manufacture many different types of semiconductorpackages using different size semiconductor die 124 from different sizedsemiconductor wafers 120.

Encapsulant or molding compound 160 is deposited over semiconductor die124 and interconnection units 600, using compressive molding, transfermolding, liquid encapsulant molding, vacuum lamination, spin coating, orother suitable applicator. Alternatively, encapsulant 160 can be formedover reconstituted wafer 170 in a chase mold. Encapsulant 160 can bepolymer composite material, such as epoxy resin with filler, epoxyacrylate with filler, or polymer with proper filler. Encapsulant 160 isnon-conductive and environmentally protects the semiconductor devicefrom external elements and contaminants. Prior to depositing encapsulant160, reconstituted wafer 170 may undergo a high pressure annealingprocess. Encapsulant 160 is formed over back surface 128 ofsemiconductor die 124, and can be thinned in a subsequent backgrindingstep. Encapsulant 160 can also be deposited such that the encapsulant iscoplanar with back surface 128. Interconnection units 600 aroundsemiconductor die 124 reduce shifting of semiconductor die 124 duringencapsulation and provide structural support during packaging.

In FIG. 4e , carrier 140 and interface layer 142 are removed fromreconstituted wafer 170 by chemical etching, mechanical peeling, CMP,mechanical grinding, thermal bake, UV light, laser scanning, or wetstripping to expose conductive layer 132, interconnection units 600, andencapsulant 160. An optional cleaning process such as a laser clean, dryplasma, or wet development may also be used.

In FIG. 4f , an insulating or passivation layer 174 is formed oversemiconductor die 124, encapsulant 160, and interconnection units 600using PVD, CVD, printing, spin coating, spray coating, sintering,thermal oxidation, or other suitable process. The insulating layer 174contains one or more layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, lowtemperature (less than 260° C.) curable polymer dielectric resist withor without filler, or other material having similar insulating andstructural properties. A portion of insulating layer 174 is removed byLDA, etching, or other suitable process to expose conductive layer 132of semiconductor die 124 and interconnection units 600 for subsequentelectrical interconnect.

An electrically conductive layer 180 is formed over insulating layer174, semiconductor die 124, and interconnection units 600 using PVD,CVD, electrolytic plating, electroless plating, or other metaldeposition suitable process. Conductive layer 180 contains one or morelayers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electricallyconductive material. Conductive layer 180 is electrically connected toconductive layer 132 and conductive vias 574. Portions of conductivelayer 180 can be electrically common or electrically isolated dependingon the design and function of semiconductor die 124 and operate as anRDL to fan-out and extend electrical connection from the semiconductordie to interconnection units 600.

In FIG. 4g , an insulating or passivation layer 182 is formed overinsulating layer 174 and conductive layer 180 using PVD, CVD, printing,spin coating, spray coating, sintering, thermal oxidation, or othersuitable process. The insulating layer 182 contains one or more layersof SiO2, Si3N4, SiON, Ta2O5, Al2O3, low temperature (less than 260° C.)curable polymer dielectric resist with or without filler, or othermaterial having similar insulating and structural properties. A portionof insulating layer 182 is removed by LDA, etching, or other suitableprocess to expose conductive layer 180 for subsequent electricalinterconnection.

An electrically conductive layer 184 is formed over conductive layer 180and insulating layer 182 using PVD, CVD, electrolytic plating,electroless plating, or other metal deposition suitable process.Conductive layer 184 contains one or more layers of Al, Cu, Sn, Ni, Au,Ag, or other suitable electrically conductive material. Conductive layer184 is electrically connected to conductive layer 180. Portions ofconductive layer 184 can be electrically common or electrically isolateddepending on the design and function of semiconductor die 124.

In FIG. 4h , an insulating or passivation layer 186 is formed overinsulating layer 182 and conductive layer 184 using PVD, CVD, printing,spin coating, spray coating, sintering, thermal oxidation, or othersuitable process. The insulating layer 186 contains one or more layersof SiO2, Si3N4, SiON, Ta2O5, Al2O3, low temperature (less than 260° C.)curable polymer dielectric resist with or without filler, or othermaterial having similar insulating and structural properties. A portionof insulating layer 186 is removed by LDA, etching, or other suitableprocess to expose conductive layer 184 for subsequent electricalinterconnect.

FIG. 4h further shows an electrically conductive bump material isdeposited over conductive layer 184 and within the openings ininsulating layer 186 using an evaporation, electrolytic plating,electroless plating, ball drop, or screen printing process. The bumpmaterial can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, and combinationsthereof, with an optional flux solution. For example, the bump materialcan be eutectic Sn/Pb, high-lead solder, or lead-free solder. The bumpmaterial is bonded to conductive layer 184 using a suitable attachmentor bonding process. In one embodiment, the bump material is reflowed byheating the material above its melting point to form balls or bumps 188.In some applications, bumps 188 are reflowed a second time to improveelectrical contact to conductive layer 184. In one embodiment, bumps 188are formed over an under bump metallization (UBM) having a wettinglayer, barrier layer, and adhesive layer. The bumps can also becompression bonded to conductive layer 184. Bumps 188 represent one typeof interconnect structure that can be formed over conductive layer 184.The interconnect structure can also use conductive paste, stud bump,micro bump, or other electrical interconnect. In some embodiments, bumps188 are formed after a second semiconductor component is disposed oversemiconductor die 124.

Taken together, insulating layers 174, 182, and 186 as well asconductive layers 180, 184, and bumps 188 form interconnect structure190. The number of insulating and conductive layers included withininterconnect structure 190 depends on, and varies with, the complexityof the circuit routing design. Accordingly, interconnect structure 190can include any number of insulating and conductive layers to facilitateelectrical interconnect with respect to semiconductor die 124. Elementsthat would otherwise be included in a backside interconnect structure orRDL can be integrated as part of interconnect structure 190 to simplifymanufacturing and reduce fabrication costs with respect to a packageincluding both front side and backside interconnects or RDLs.

In FIG. 4i , an optional carrier or temporary substrate 202 similar tocarrier 140 is disposed over interconnect structure 190. Carrier 202 maybe a backgrinding tape, supporting tape, and other carriers containingsacrificial base material such as silicon, polymer, beryllium oxide,glass, or other suitable low-cost, rigid material for structuralsupport. Carrier 202 can include an interface layer, such as adouble-sided tape, configured to receive interconnect structure 190.Carrier 202 optionally provides additional support for subsequentprocessing steps of a semiconductor package, as shown in FIGS. 4i-4n .Alternatively, the subsequent processing steps are performed withoutcarrier 202.

FIG. 4i further shows top surface of encapsulant 160 opposite bumps 188in a grinding operation with grinder 206 to planarize the surface andreduce a thickness of the encapsulant 160. A chemical etch or CMPprocess can also be used to remove mechanical damage and planarizeencapsulant 160 with back surface 128. In one embodiment, after removalof a portion of encapsulant 160, encapsulant 160 has a thickness in arange of 100 to 400 μm. The grinding operation removes a portion ofencapsulant 160 down to back surface 128 of semiconductor die 124.Alternatively, a layer of encapsulant 160 remains over back surface 128of semiconductor die 124. In some embodiments, grinding operationexposes conductive layer 576 and may expose conductive material 574 ofinterconnection units 600. Alternatively, a portion of encapsulant 160remains over interconnection units 600.

In FIG. 4j , an insulating layer, polymer matrix composite film, orwarpage balance layer 210 is formed over back surface 128 ofsemiconductor die 124, encapsulant 160, and interconnection units 600.Insulating layer 210 includes an epoxy, resin, or polymer with areinforcement fiber or fabric, such as phenolic cotton paper, epoxy,resin, woven glass, matte glass, polyester, and other reinforcementfibers or fabrics. In another embodiment, insulating layer 210 containsa molding compound, polymer dielectric with or without fillers, one ormore layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, polymer matrix enhancedwith woven glass fiber, or other material having similar insulating andstructural properties. In yet another embodiment, insulating layer 210includes one or more laminated layers of prepreg, FR epoxy-4, FR-1,CEM-1, or CEM-3. Insulating layer 210 is deposited using vacuum orpressure lamination with or without heat, PVD, CVD, screen printing,spin coating, spray coating, injection coating, sintering, thermaloxidation, or other suitable process. The insulating layer 210 isselected to have a coefficient of thermal expansion (CTE) similar to aCTE of Cu, i.e., within 10 ppm/° C. of the CTE of Cu. The materialselected for insulating layer 210, such as prepreg, enhances the overallstrength of the semiconductor package and improves package warpage,particularly at temperatures of 150° C. to 260° C. Insulating layer 210balances warpage across the semiconductor device and provides additionalsupport during subsequent device integration. Insulating layer 210 alsoprotects exposed portions of the semiconductor die 124. In someembodiments, semiconductor die 124 is completely embedded by insulatinglayer 210, encapsulant 160, and interconnect structure 190.

In FIG. 4k , a portion of insulating layer 210 and encapsulant 160 isremoved by LDA, etching, or other suitable process to form vias oropenings 216 through insulating layer 210 and encapsulant 160 to exposeconductive vias 574 of interconnection units 600. In some embodiments,formation of vias 216 further includes the removal of a portion ofinsulating layer 578.

In some embodiments, after formation of vias 216, an electricallyconductive bump material is deposited in vias 216 and overinterconnection units 600 using an evaporation, electrolytic plating,electroless plating, ball drop, screen printing, paste printing,jetting, or other suitable process. The bump material can be Al, Sn, Ni,Au, Ag, Pb, Bi, Cu, solder, and combinations thereof, with an optionalflux solution. The flux solution is spin coated, stencil printed, orapplied in a dipping process. The flux solution is non-clean flux withsolvent, or a water clean flux. The bump material can be eutectic Sn/Pb,high-lead solder, or lead-free solder. The bump material is bonded tointerconnection units 600 using a suitable attachment or bondingprocess. In some embodiments, bump material is bonded to a solder capformed on conductive layer 576. In one embodiment, the bump material isreflowed by heating the material above its melting point to form ballsor bumps 224, as shown in FIG. 4m . In some applications, bumps 224 arereflowed a second time to improve electrical contact to interconnectionunits 600. Bumps 224 can be reflowed with or without support fromcarrier 202 and with support from a separate carrier. In one embodiment,bumps 224 are formed over a UBM having a wetting layer, barrier layer,and adhesive layer. Bumps 224 can also be compression bonded tointerconnection units 600. Bumps 224 represent one type of interconnectstructure that can be formed over interconnection units 600. Theinterconnect structure can also use conductive paste, stud bump, microbump, solder balls with a Cu core, Cu balls or columns with dippedsolder paste or solder coating, or other electrical interconnectdisposed within vias 216.

Bumps 224 together with interconnect structure 190, interconnectionunits 600, and semiconductor die 124 form a 3D interconnection for nextlevel interconnect. In one embodiment, bumps 224 are formed by surfacemount technology (SMT) with paste printing deposited into vias 216 atthe reconstituted wafer level. After the formation of bumps 224, anoptional polymer dielectric paste plugging may be applied over andaround the bumps to provide additional support. The polymer dielectricpaste plugging is applied through printing, spray coating, dipping,jetting, or other suitable process and is followed by an optional reflowor heat treatment under vacuum. Alternatively, bumps are later formed onan external semiconductor package, as shown in FIG. 4 l.

FIG. 4k further shows composite substrate or reconstituted wafer 170 issingulated using a saw blade or laser cutting tool 226 into individualsemiconductor packages 227. By singulating reconstituted wafer 170before mounting additional semiconductor devices over the reconstitutedwafer 170, the formation of a semiconductor package is accomplished bymounting additional semiconductor devices to individual semiconductorpackages 227 rather than at the reconstituted wafer level.Alternatively, reconstituted wafer 170 is singulated after additionalsemiconductor devices are mounted to the reconstituted wafer 170.Semiconductor packages 227 may undergo electrical testing before orafter singulation.

After singulating the semiconductor device into individual semiconductorpackages 227 and removing carrier 202, an optional carrier, carriertray, or temporary substrate 228 is disposed over interconnect structure190, as shown in FIG. 4l . Alternatively, carrier 202 is singulatedalong with reconstituted wafer 170. Carrier 228 includes a backgrindingtape, supporting tape, and other carriers containing sacrificial basematerial such as silicon, polymer, beryllium oxide, glass, or othersuitable low-cost, rigid material for structural support. Carrier 228can include an interface layer, double-sided tape, and openingsconfigured to receive composite substrate 170 or semiconductor packages227 and interconnect structure 190. Carrier 228 optionally providesadditional support for subsequent processing steps of the semiconductorpackage, as shown in FIGS. 4l-4n . Alternatively, the subsequentprocessing steps are performed without carrier 228.

FIG. 4l further shows semiconductor package, semiconductor die, orsemiconductor component 230, singulated from a semiconductor wafersimilar to FIGS. 3a-3c , with a back surface 252 and active surface 254containing analog or digital circuits implemented as active devices,passive devices, conductive layers, and dielectric layers formed withinthe die and electrically interconnected according to the electricaldesign and function of the die. For example, the circuit may include oneor more transistors, diodes, and other circuit elements formed withinactive surface 254 to implement analog circuits or digital circuits,such as a DSP, ASIC, memory, or other signal processing circuit.Semiconductor die 230 may also contain IPDs, such as inductors,capacitors, and resistors, for RF signal processing. Semiconductor die230 undergo electrical testing before or after singulation from asemiconductor wafer similar to semiconductor die 124 of FIGS. 3a -3 c.

An insulating or passivation layer 255 is formed over semiconductor die230 using PVD, CVD, printing, spin coating, spray coating, sintering,thermal oxidation, or other suitable process. The insulating layer 255contains one or more layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, or othermaterial having similar insulating and structural properties. A portionof insulating layer 255 is removed by LDA, etching, or other suitableprocess for subsequent electrical interconnect.

An electrically conductive layer 256 is formed over active surface 254using PVD, CVD, electrolytic plating, electroless plating process, orother suitable metal deposition process. Conductive layer 256 can be oneor more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitable electricallyconductive material. Conductive layer 256 operates as contact pads 256electrically connected to the circuits on active surface 254. Conductivelayer 256 can be formed as contact pads 256 disposed side-by-side afirst distance from the edge of semiconductor die 230. Alternatively,conductive layer 256 can be formed as contact pads that are offset inmultiple rows such that a first row of contact pads is disposed a firstdistance from the edge of the die, and a second row of contact padsalternating with the first row is disposed a second distance from theedge of the die.

An electrically conductive bump material is deposited over conductivelayer 256 using an evaporation, electrolytic plating, electrolessplating, ball drop, or screen printing process. The bump material can beAl, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, and combinations thereof, withan optional flux solution. For example, the bump material can beeutectic Sn/Pb, high-lead solder, or lead-free solder. The bump materialis bonded to conductive layer 256 using a suitable attachment or bondingprocess. In some embodiments, the bump material is reflowed by heatingthe material above its melting point to form balls or bumps 258. In someapplications, bumps 258 are reflowed a second time to improve electricalcontact to conductive layer 256. In some embodiments, bumps 258 areformed over a UBM having a wetting layer, barrier layer, and adhesivelayer. The bumps can also be compression bonded or thermocompressionbonded to conductive layer 256. Bumps 258 represent one type ofinterconnect structure that can be formed over conductive layer 256. Theinterconnect structure can also use conductive paste, stud bump, microbump, or other electrical interconnect.

In some embodiments, bumps 258 form part of a BGA formed over conductivelayer 256. The BGA is formed such that bumps 258 align with theorientation of vias 216 over interconnection units 600. Alternatively, afirst portion of bumps 258 align with vias 216 over interconnectionunits 600 and a second portion of bumps 258 are isolated frominterconnection units 600 or form part of additional interconnectstructures around semiconductor die 230.

Using a pick and place operation, semiconductor die 230 is mounted toindividual semiconductor package 227 with active surface 254 orientedtoward vias 216 and bumps 258 extending into vias 216 to contactinterconnection units 600. As previously discussed, bumps 224 may bepre-formed within vias 216 prior to stack assembly (FIG. 4m ). In someembodiments, semiconductor die 230 has a width that is larger than awidth of semiconductor die 124. Semiconductor die 230 can be locatedoutside or partially outside a footprint of semiconductor die 124 aftersemiconductor die 230 has been mounted to semiconductor package 227. Insome embodiments, an interconnect structure is formed over activesurface 254 of semiconductor die 230 and bumps 258 are formed over asurface of the interconnect structure. In other embodiments,semiconductor die 230 does not have bumps 258 and semiconductor die 230connects with individual semiconductor package 227 at interconnectionunits 600 through bumps 224 preformed in vias 216, as shown in FIG. 4m .In another embodiment, semiconductor die 230 connects with individualsemiconductor package 227 at interconnection units 600 through thecombination of bumps 258 and an interconnect structure, or through aninterconnect structure without bumps 258. The formation of bumps 258 canbe conducted just before or during mounting of semiconductor die 230 toindividual semiconductor package 227.

Before mounting semiconductor die 230 over individual semiconductorpackage 227, an underfill material 260, epoxy-resin adhesive material,epoxy compound, or molding material is disposed over insulating layer210 within a footprint of semiconductor package 227, as shown in FIG. 4n. Dotted line 261 indicates a die attach area for semiconductor die 230.Underfill material 260 is applied by balance position as dots disposedover insulating layer 210 within a footprint of individual semiconductorpackage 227. Underfill material 260 supports semiconductor die 230during stack assembly and mounting of semiconductor die 230 overindividual semiconductor package 227. Alternatively, or in combinationwith underfill material 260, a non-conductive paste is disposed overinsulating layer 210 to provide additional support during stack assemblyand mounting of semiconductor die 230 over individual semiconductorpackage 227. Underfill material 260 provides support during mounting andduring a subsequent reflow process. Underfill material 260 mayoptionally be disposed on active surface 254 of semiconductor die 230.

In some embodiments, bumps 258 form part of an interconnect structuredisposed over active surface 254 of semiconductor die 230 to facilitatererouting of semiconductor die 230, similar to interconnect structure190. Bumps 258 can extend from an interconnect structure such that theinterconnect structure, bumps 258, interconnect structure 190, andinterconnection units 600 make up an L-shaped interconnect formed fromsemiconductor package 227 to semiconductor die 230.

Carrier 228 is removed after or during stack assembly by chemicaletching, mechanical peeling, CMP, mechanical grinding, thermal bake, UVlight, laser scanning, or wet stripping. An optional encapsulant may bedeposited over semiconductor package 227 and semiconductor die 230.

FIG. 5 shows semiconductor package 300 formed using the processillustrated in FIGS. 4a-4n after separation from carrier 228 withsemiconductor die 230 and bumps 258 mounted over semiconductor die 124.In some embodiments, semiconductor die 230 is laterally offset oversemiconductor die 124 such that semiconductor die 230 is disposed over aportion of semiconductor die 124. Interconnection units 600 are disposedwithin semiconductor package 300, perpendicular to interconnectstructure 190, and extend vertically over interconnect structure 190. Insome embodiments, a height of bumps 258 combined with interconnectionunits 600 is greater than a thickness of semiconductor die 124. Thus, agap exists between active surface 254 and back surface 128. Insulatinglayer 210 is interposed in the gap between active surface 254 and backsurface 128. Alternatively, a height of bumps 258 combined withinterconnection units 600 is equal to or less than a thickness ofsemiconductor die 124. Active surface 254 of semiconductor die 230 mayrest on insulating layer 210 over back surface 128 with no gap betweenactive surface 254 and back surface 128. Insulating layer 210 formedover back surface 128 and encapsulant 160 and interposed between activesurface 254 and back surface 128 provides physical support, controlsoverall package warpage, and environmentally protects semiconductor die124 from external elements and contaminants. Insulating layer 210provides structural support for semiconductor package 300, balancesstress on the package, and reduces warping or cracking of package 300during subsequent handling and processing.

Semiconductor package 300 provides 3D vertical electricalinterconnection through a combination of interconnect structure 190,interconnection units 600, and bumps 258. The vertical interconnectionis formed with reduced backside RDL. Interconnect structure 190 isformed over active surface 130 of semiconductor die 124 and overencapsulant 160 with a portion of interconnect structure 190 around theperiphery of the semiconductor die 124. Interconnect structure 190includes insulation and conductive layers that form a fan-outinterconnect structure and includes elements that would otherwise beincluded in a backside RDL or interconnect structure. Interconnectionunits 600 provide vertical interconnect to reduce RDL layers, andprovide a partial backside RDL without the cost and more difficultmanufacturing processes associated with forming a complete RDL layer ormultiple RDLs over a backside of semiconductor package 300. Usinginterconnection units 600 within semiconductor package 300 providesdesign flexibility and reduces the height of semiconductor package 300.Semiconductor package 300 is a low profile 3D package structure.

Using prefabricated modular interconnection units 600 providesadditional flexibility during packaging because interconnection units600 can be mounted to carrier 140 or semiconductor package 300 atvarious stages of the packaging process. Mounting interconnection units600 using an adhesive does not require formation of layers over acarrier 140 during packaging of semiconductor package 300.Interconnection units 600 are modular units that can be disposed withinor removed from a semiconductor package such as semiconductor package300, unlike layers formed within a semiconductor package.Interconnection units 600 disposed around semiconductor die 124 providevertical interconnect with reduced RDL application. Interconnectionunits 600 formed around semiconductor die 124 provide structural supportduring packaging and reduce shifting during the application ofencapsulant 160 and external semiconductor components such assemiconductor die 230. In some embodiments, a continuous verticalinterconnect along a vertical plane is made from conductive layer 256,through bumps 258, interconnection units 600, conductive layer 180,conductive layer 184, to bumps 188. True 3D interconnection is achievedwith semiconductor package 300 while reducing the height ofsemiconductor package 300. As vertical structures, interconnection units600 can form a border, frame, slot, or other similar support structurearound a side portion or peripheral region of semiconductor die 124 inaddition to providing vertical electrical interconnect. Interconnectionunits 600 reduce the quantity of RDLs formed within a package.Interconnection units 600 provide partial backside RDL without the cost,time, and other manufacturing restraints associated with formingmultiple RDLs in a semiconductor package. Interconnection units 600provide design flexibility while reducing z-direction package height.

Bumps 258, or interconnect structures of an external device such assemiconductor die 230, can be disposed or formed on semiconductor die230 in an orientation matching the layout or orientation ofinterconnection units 600 disposed around semiconductor die 124.Matching bumps 258 or interconnect structures of semiconductor die 230with the layout of interconnection units 600 reduces manufacturingmaterials and cost. Matching interconnection units 600 with bumps 258 orinterconnect structures of semiconductor die 230 provides a consistentand reliable 3D vertical interconnect. In some embodiments, interconnectstructure 190 further matches the orientation of interconnection units600 around semiconductor die 124.

Creating vertical interconnect by disposing interconnection units 600 asopposed to build-up layers and RDLs provides enhanced flexibility forpackaging design. Interconnection units 600 do not have to be disposedover an entire surface area and can be disposed as modular units atcustomized locations within a semiconductor package 300, which isdifficult to accomplish with other interconnect structures. For example,disposing interconnection units 600 over first side portions of thesemiconductor die 124 and not around second side portions of thesemiconductor die 124 can free valuable space within semiconductorpackage 300 and expose the second side portions around semiconductor die124 for additional electrical components. Alternatively, where increasedvertical interconnect density is desired, interconnection units 600 cancompletely surround semiconductor die 124 for a dense yet flexiblevertical interconnect. Interconnection units 600 conserve materialswhile optimizing the space within semiconductor package 300.

FIGS. 6a-6h illustrate a process flow for an alternative embodiment of asemiconductor package, formed with a process similar to thesemiconductor package 300 in FIGS. 4a-4n . FIG. 6a shows across-sectional view of a portion of a carrier or temporary substrate308, similar to carrier 140 of FIG. 4a , containing sacrificial basematerial such as silicon, polymer, beryllium oxide, glass, or othersuitable low-cost, rigid material for structural support. An interfacelayer or double-sided tape 310 is formed over carrier 308 as a temporaryadhesive bonding film, etch-stop layer, or thermal release layer.

FIG. 6a shows semiconductor die 124 from FIG. 3c mounted to interfacelayer 310 using, for example, a pick and place operation with activesurface 130 oriented toward carrier 308. Semiconductor die 124 mountedto die attach area 150 can be chosen from KGD. Semiconductor die 124 arepressed into interface layer 310 such that a portion of insulating layer134 is disposed within and surrounded by the interface layer.

Prefabricated modular interconnection units or interconnect structures326, similar to interconnection units 600, are mounted to interfacelayer 310 with an optional adhesive. Similar to interconnection units600, interconnection units 326 are prefabricated with a typical laminatesubstrate at the panel/strip level and singulated into individualinterconnection units 326. Interconnection units 326 includeinterconnect layer 312, core substrate 323, and conductive vias 324.Interconnection units 326 are disposed a distance from the carrier edge,i.e., a gap or space remains between the carrier edge andinterconnection units 326. Alternatively, interconnection units 326extend to the edge of carrier 308. Interconnection units 326 aredisposed a distance from semiconductor die 124, i.e., a gap or spaceremains between semiconductor die 124 and interconnection units 326.

Interconnect layer 312 includes a first insulating or passivation layer316 over core substrate 323 containing one or more layers of SiO2,Si3N4, SiON, Ta2O5, Al2O3, or other material having similar insulatingand structural properties. Insulating layer 316 is formed using PVD,CVD, printing, spin coating, spray coating, sintering or thermaloxidation.

Interconnect layer 312 includes a first electrically conductive layer318 formed in insulating layer 316 using a patterning and metaldeposition process such as PVD, CVD, sputtering, electrolytic plating,and electroless plating. Conductive layer 318 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. Conductive layer 318 serves as a Cu pad for interconnectionunits 326.

Interconnect layer 312 further includes a second insulating orpassivation layer 320 formed over conductive layer 318 and insulatinglayer 316 containing one or more layers of SiO2, Si3N4, SiON, Ta2O5,Al2O3, or other material having similar insulating and structuralproperties. Insulating layer 320 is formed using PVD, CVD, printing,spin coating, spray coating, sintering or thermal oxidation.

Interconnect layer 312 further includes a second electrically conductivelayer 322 formed over insulating layer 320 and conductive layer 318using a patterning and metal deposition process such as PVD, CVD,sputtering, electrolytic plating, and electroless plating. Conductivelayer 322 can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or othersuitable electrically conductive material. Conductive layer 322 iselectrically connected to conductive layer 318 and conductive vias 324.Other portions of conductive layer 322 can be electrically common orelectrically isolated depending on the design and function of thesemiconductor device.

FIG. 6b shows interconnection units 326 mounted to interface layer 310around semiconductor die 124. Interconnection units 326 are mounted oninterface layer 310 over opposing sides of semiconductor die 124, asshown in FIG. 6c , with active surface 130 of semiconductor die 124oriented toward interface layer 310 and interconnect layer 312 ofinterconnection units 326 opposite interface layer 310.

FIG. 6b further shows encapsulant or molding compound 325 deposited oversemiconductor die 124, interconnection units 326, carrier 308, andinterface layer 310 using a paste printing, compressive molding,transfer molding, liquid encapsulant molding, vacuum lamination, spincoating, or other suitable applicator. Alternatively, encapsulant 325 isapplied using a chase mold. Encapsulant 325 can be polymer compositematerial, such as epoxy resin with filler, epoxy acrylate with filler,or polymer with proper filler. Encapsulant 325 is non-conductive andenvironmentally protects the semiconductor device from external elementsand contaminants. Encapsulant 325 is formed over back surface 128 ofsemiconductor die 124, and can be thinned in a subsequent backgrindingstep.

FIG. 6c shows a top view of the semiconductor package from FIG. 6b ,before encapsulant 325, and after mounting interconnection units 326 tointerface layer 310. In some embodiments, interconnection units 326 aredisposed over opposing sides of semiconductor die 124. Dotted line 261represents a die attach area for the later mounting of semiconductor die230.

In FIG. 6d , carrier 308 and interface layer 310 are removed by chemicaletching, mechanical peeling, chemical mechanical planarization CMP,mechanical grinding, thermal bake, UV light, laser scanning, or wetstripping. An optional cleaning process such as a laser clean, dryplasma, or wet development may also be used.

In FIG. 6e , an additional build-up interconnect structure 330 is formedover encapsulant 325, active surface 130, and interconnection units 326.Interconnect structure 330 includes a cavity 338 formed in interconnectstructure 330 over semiconductor die 124. In some embodiments, cavity338 is a die attach area. In some embodiments, cavity 338 exposes activesurface 130 over the cavity for the subsequent mounting of semiconductordie 230 directly to semiconductor die 124. In some embodiments, as shownin FIG. 6e , a thinned portion of interconnect structure 330 remainsover semiconductor die 124 such that active surface 130 is not exposedby cavity 338. During the formation of interconnect structure 330,insulating layer 327 may be either partially removed or fully removed bypartial mechanical grinding or laser ablation.

Interconnect structure 330 includes an insulating or passivation layer332 containing one or more layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, orother material having similar insulating and structural properties.Insulating layer 332 is formed using PVD, CVD, printing, spin coating,spray coating, sintering or thermal oxidation.

Interconnect structure 330 includes an electrically conductive layer 334formed in insulating layer 332 using a patterning and metal depositionprocess such as PVD, CVD, sputtering, electrolytic plating, andelectroless plating. Conductive layer 334 can be one or more layers ofAl, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial. In some embodiments, a portion of conductive layer 334 iselectrically connected to interconnection units 326 and a portion ofconductive layer 334 is electrically connected to conductive layer 132over active surface 130. Other portions of conductive layer 334 can beelectrically common or electrically isolated depending on the design andfunction of the semiconductor device.

Interconnect structure 330 further includes an electrically conductivelayer 336 formed in insulating layer 332 and over conductive layer 334using a patterning and metal deposition process such as PVD, CVD,sputtering, electrolytic plating, and electroless plating. Conductivelayer 336 can be one or more layers of Al, Cu, Sn, Ni, Au, Ag, or othersuitable electrically conductive material. In some embodiments, aportion of conductive layer 336 is electrically connected to conductivelayer 334. Other portions of conductive layer 336 can be electricallycommon or electrically isolated depending on the design and function ofthe semiconductor device.

In FIG. 6f , a surface of encapsulant 325 opposite interconnectstructure 330 undergoes a grinding operation with grinder 206 toplanarize the surface and reduce a thickness of the encapsulant 325,exposing conductive layer 318. Alternatively, shallow LDA is used toexpose conductive layer 318 of interconnection units 326 throughencapsulant 325.

In FIG. 6g , a semiconductor package, semiconductor die, orsemiconductor component 230, singulated from a semiconductor wafersimilar to FIGS. 3a-3c , is disposed over cavity 338. Using a pick andplace operation, semiconductor die 230 is mounted within cavity 338 ofinterconnect structure 330. Bumps 258 of semiconductor die 230 arebonded to conductive portions, such as conductive layer 334, ofinterconnect structure 330 within cavity 338 and over active surface 130of semiconductor die 124. Alternatively, cavity 338 exposes activesurface 130 and semiconductor die 230 connects directly with conductivelayer 132 over active surface 130 through bumps 258. In someembodiments, semiconductor die 230 has a width that is less than a widthof semiconductor die 124. In some embodiments, semiconductor die 230 isdisposed over a footprint of semiconductor die 124. In some embodiments,semiconductor die 230 does not have bumps 258 and instead bumps arepreformed within cavity 338.

FIG. 6g further shows a mechanical support layer 346 formed over backsurface 128 using printing, spin coating, spray coating, screenprinting, stencil printing, jetting, lamination, or other suitableprocess. An optional cleaning process such as a laser clean, dry plasma,or wet development may also be used. Materials of mechanical supportlayer 346 include one or more layers of photosensitive polymerdielectric film with or without fillers, photosensitive compositeresist, non-photosensitive polymer dielectric film, liquid crystalpolymer (LCP), laminate compound film, insulation paste with filler,liquid molding compound, granular molding compound, polyimide, polymerflux, underfill, or other material having similar insulating andstructural properties. One or more portions of mechanical support layer346 are removed using LDA. Mechanical support layer 346 providesstructural support, balances stress on the semiconductor package, andreduces warping and cracking. In one embodiment, mechanical supportlayer 346 is laminated on back surface 128 of semiconductor die 124 andencapsulant 325 before conducting laser ablation to expose conductivelayer 318.

FIG. 6h shows semiconductor die 230 mounted within cavity 338 ofinterconnect structure 330 over active surface 130 of semiconductor die124 as a semiconductor package 306. Carrier 308 and interface layer 310are removed by chemical etching, mechanical peeling, chemical mechanicalplanarization CMP, mechanical grinding, thermal bake, UV light, laserscanning, or wet stripping. An optional cleaning process such as a laserclean, dry plasma, or wet development may also be used.

An optional underfill material 340 is disposed between semiconductor die230 and active surface 130 around bumps 258. In some embodiments, asshown in FIG. 6h , semiconductor die 230 extends above a thickness ofinterconnect structure 330. Alternatively, semiconductor die 230 maycomprise a thickness such that upon mounting semiconductor die 230within cavity 338, back surface 252 is coplanar with a surface ofinterconnect structure 330 opposite the surface formed overinterconnection units 326 or is below the surface. At least a portion ofinterconnection units 326 is completely embedded by encapsulant 325 andinterconnect structure 330.

FIG. 6h further shows an electrically conductive bump material isdeposited over conductive layer 318 of interconnection units 326 usingan evaporation, electrolytic plating, electroless plating, ball drop, orscreen printing process. The bump material can be Al, Sn, Ni, Au, Ag,Pb, Bi, Cu, solder, and combinations thereof, with an optional fluxsolution. For example, the bump material can be eutectic Sn/Pb,high-lead solder, or lead-free solder. The bump material is bonded toconductive layer 318 using a suitable attachment or bonding process. Inone embodiment, the bump material is reflowed by heating the materialabove its melting point to form balls or bumps 348. In someapplications, bumps 348 are reflowed a second time to improve electricalcontact to conductive layer 318. In one embodiment, bumps 348 are formedover a UBM having a wetting layer, barrier layer, and adhesive layer.The bumps can also be compression bonded to conductive layer 318. Bumps348 represent one type of interconnect structure that can be formed overconductive layer 318. The interconnect structure can also use conductivepaste, stud bump, micro bump, or other electrical interconnect.

Modular interconnection units 326 disposed around semiconductor die 124provide vertical interconnect with reduced RDL application.Interconnection units 326 disposed along one side or in an L-shapedconfiguration around semiconductor die 124, similar to FIG. 4c , providestructural support during packaging and reduce shifting during theapplication of encapsulant 325 and external semiconductor componentssuch as semiconductor die 230. Interconnection units 326 can form aborder, frame, slot, or other similar support structure around a sideportion or portions or over a peripheral region of semiconductor die124. Interconnection units 326 reduce the quantity of RDLs formed withina package. Interconnection units 326 provide partial backside RDLwithout the cost, time, and other manufacturing restraints associatedwith forming multiple RDLs in a semiconductor package. Interconnectionunits 326 provide design flexibility while reducing z-direction packageheight.

Bumps 258, or interconnect structures of an external device such assemiconductor die 230, can be disposed or formed on semiconductor die230 in an orientation matching the layout or orientation ofinterconnection units 326 disposed around semiconductor die 124.Matching bumps 258 or interconnect structures of semiconductor die 230with the layout of interconnection units 326 reduces manufacturingmaterials and cost. Matching interconnection units 326 with bumps 258 orinterconnect structures of semiconductor die 230 provides a consistentand reliable 3D vertical interconnect.

Creating vertical interconnect by disposing interconnection units 326 asopposed to build-up layers and RDLs provides enhanced flexibility forpackaging design. Interconnection units 326 do not have to be disposedover an entire surface area and can be disposed at customized locationswithin semiconductor package 306 package which is difficult toaccomplish with other interconnect structures. For example, disposinginterconnection units 326 over first side portions of the semiconductordie 124 and not around second side portions of the semiconductor die 124can free valuable space within the semiconductor package 306 and exposethe second side portions around semiconductor die 124 for additionalelectrical components. Alternatively, where increased verticalinterconnect density is desired, interconnection units 326 cancompletely surround semiconductor die 124 for a dense yet flexiblevertical interconnect. Interconnection units 326 help to conservematerials and also optimize the space within semiconductor package 306.

FIG. 7 shows an alternative embodiment of a semiconductor package 350,formed with a process similar to the semiconductor package 306 in FIGS.6a-6h . With semiconductor package 350, bumps 348 are removed andreplaced with LGA pads 352 formed over or within interconnect layer 312.LGA pads 352 provide I/O instead of bumps 348 for the semiconductorpackage 350 to reduce a height or thickness of the package.

Mechanical support layer 346 is also removed from semiconductor package350. The removal of mechanical support layer 346 and bumps 348 fromsemiconductor package 350 provides a reduced profile and reducesmanufacturing steps. In some embodiments, semiconductor package 350includes a bottom surface coplanar with back surface 128, bottom surfaceof interconnect layer 312, and a bottom surface of encapsulant 325. Assuch, a slim, yet robust profile is provided for semiconductor package350.

FIGS. 8a-8g illustrate a process flow for an alternative embodiment of asemiconductor package, formed with a process similar to thesemiconductor package 306 illustrated in FIGS. 6a-6h . FIG. 8a shows across-sectional view of a portion of a carrier or temporary substrate308, similar to carrier 140 of FIG. 4a , containing sacrificial basematerial such as silicon, polymer, beryllium oxide, glass, or othersuitable low-cost, rigid material for structural support. An interfacelayer or double-sided tape 310 is formed over carrier 308 as a temporaryadhesive bonding film, etch-stop layer, or thermal release layer.

FIG. 8a shows semiconductor die 124 from FIG. 3c mounted to interfacelayer 310 using, for example, a pick and place operation with activesurface 130 oriented toward the carrier 308. Semiconductor die 124mounted to die attach area 150 can be chosen from KGD. Semiconductor die124 are pressed into interface layer 310 such that a portion ofinsulating layer 134 is disposed within and surrounded by the interfacelayer.

Prefabricated modular interconnection units or interconnect structures364, similar to interconnection units 326 in FIG. 6a , are mounted tointerface layer 310 with an optional adhesive. Similar tointerconnection units 600, interconnection units 364 are prefabricatedwith a typical laminate substrate at the panel/strip level andsingulated into individual interconnection units 364. Interconnectionunits 364 include interconnect layer 366, insulating layer 362,conductive material 363, and interconnect layer 374. Interconnectionunits 364 are disposed a distance from semiconductor die 124. A gap orspace remains between semiconductor die 124 and interconnection units364.

Interconnect layer 366 is part of interconnection units 364 and providesadditional vertical interconnect including a Cu pad for interconnectionunits 364. As a part of interconnection units 364, interconnect layer366 extends from and is within a footprint of interconnection units 364.Interconnect layer 366 includes an insulating or passivation layer 367containing one or more layers of SiO2, Si3N4, SiON, Ta2O5, Al2O3, orother material having similar insulating and structural properties.Insulating layer 367 is formed using PVD, CVD, printing, spin coating,spray coating, sintering or thermal oxidation.

Interconnect layer 366 further includes an electrically conductive layer368 formed in insulating layer 367 using a patterning and metaldeposition process such as PVD, CVD, sputtering, electrolytic plating,and electroless plating. Conductive layer 368 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial.

Interconnect layer 366 further includes an electrically conductive layer370 formed in insulating layer 367 and over conductive layer 368 using apatterning and metal deposition process such as PVD, CVD, sputtering,electrolytic plating, and electroless plating. Conductive layer 370 canbe one or more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitableelectrically conductive material. In some embodiments, a portion ofconductive layer 370 is electrically connected to conductive layer 368.Other portions of conductive layer 370 can be electrically common orelectrically isolated depending on the design and function of thesemiconductor device. Conductive layer 370 forms Cu pads forinterconnection units 364.

Interconnect layer 374, opposite interconnect layer 366, is part ofinterconnection units 364. As a part of interconnection units 364,interconnect layer 374 extends from and is within a footprint ofinterconnection units 364. Interconnect layer 374 includes an insulatingor passivation layer 375 containing one or more layers of SiO2, Si3N4,SiON, Ta2O5, Al2O3, or other material having similar insulating andstructural properties. Insulating layer 375 is formed using PVD, CVD,printing, spin coating, spray coating, sintering or thermal oxidation.

Interconnect layer 374 further includes an electrically conductive layer376 formed in insulating layer 375 using a patterning and metaldeposition process such as PVD, CVD, sputtering, electrolytic plating,and electroless plating. Conductive layer 376 can be one or more layersof Al, Cu, Sn, Ni, Au, Ag, or other suitable electrically conductivematerial.

Interconnect layer 374 further includes an electrically conductive layer378 formed in insulating layer 375 and over conductive layer 376 using apatterning and metal deposition process such as PVD, CVD, sputtering,electrolytic plating, and electroless plating. Conductive layer 378 canbe one or more layers of Al, Cu, Sn, Ni, Au, Ag, or other suitableelectrically conductive material. In some embodiments, a portion ofconductive layer 378 is electrically connected to conductive layer 376.Other portions of conductive layer 378 can be electrically common orelectrically isolated depending on the design and function of thesemiconductor device.

FIG. 8b shows interconnection units 364 mounted to interface layer 310around semiconductor die 124. Interconnection units 364 are mounted oninterface layer 310 over a side portion of semiconductor die 124.

FIG. 8b further shows encapsulant or molding compound 372 deposited oversemiconductor die 124, interconnection units 364, carrier 308, andinterface layer 310 using a paste printing, compressive molding,transfer molding, liquid encapsulant molding, vacuum lamination, spincoating, or other suitable applicator. Alternatively, encapsulant 372 isapplied using a chase mold. Encapsulant 372 can be polymer compositematerial, such as epoxy resin with filler, epoxy acrylate with filler,or polymer with proper filler. Encapsulant 372 is non-conductive andenvironmentally protects the semiconductor device from external elementsand contaminants. Encapsulant 372 is formed over back surface 128 ofsemiconductor die 124.

In FIG. 8c , build-up interconnect structure 382 is formed over asurface of insulating layer 375, insulating layer 134, active surface130, and encapsulant 372. Interconnect structure 382 includes aninsulating or passivation layer 383 formed over encapsulant 372,insulating layer 134, insulating layer 375, conductive layer 378, andactive surface 130. In some embodiments, insulating layer 383 containsone or more layers of low temperature curable polymer dielectric resist(i.e., cures at less than 260° C.) with or without filler, SiO2, Si3N4,SiON, Ta2O5, Al2O3, or other material having similar insulating andstructural properties. Insulating layer 383 is deposited using PVD, CVD,printing, spin coating, spray coating, sintering, thermal oxidation, orother suitable process. A portion of insulating layer 383 is removed byLDA, etching, or other suitable process to form openings over conductivelayer 132. The openings expose conductive layer 132 of semiconductor die124 for subsequent electrical interconnect.

An electrically conductive layer 384 is formed over insulating layer383, insulating layer 134, over semiconductor die 124 andinterconnection units 364, and disposed within openings in insulatinglayer 383 to fill the openings and contact conductive layer 132. The oneor more layers of conductive layer 384 include Al, Cu, Sn, Ni, Au, Ag,or other suitable electrically conductive material. The deposition ofconductive layer 384 uses PVD, CVD, electrolytic plating, electrolessplating, or other suitable process. In some embodiments, conductivelayer 384 operates as an RDL to fan-out and extend electrical connectionfrom semiconductor die 124 to points external to semiconductor die 124such as interconnection units 364.

An insulating or passivation layer 385 is conformally applied to, andfollows the contours of, insulating layer 383 and conductive layer 384.Insulating layer 385 contains one or more layers of low temperaturecurable polymer dielectric resist (i.e., cures at less than 260° C.)with or without filler, SiO2, Si3N4, SiON, Ta2O5, Al2O3, or othermaterial having similar insulating and structural properties. Insulatinglayer 385 is deposited using PVD, CVD, printing, spin coating, spraycoating, sintering, thermal oxidation, or other suitable process. Aportion of insulating layer 385 is removed by an exposure or developmentprocess, LDA, etching, or other suitable process to form openings in theinsulating layer, which expose portions of conductive layer 384 forsubsequent electrical interconnection.

An electrically conductive layer 386 is formed over insulating layer385, over conductive layer 384, and disposed within the openings ininsulating layer 385 to fill the openings and contact conductive layer384. The one or more layers of conductive layer 386 include Al, Cu, Sn,Ni, Au, Ag, or other suitable electrically conductive material. Thedeposition of conductive layer 386 uses PVD, CVD, electrolytic plating,electroless plating, or other suitable process. In some embodiments,conductive layer 386 operates as an RDL to fan-out and extend electricalconnection from semiconductor die 124 to points external tosemiconductor die 124.

In FIG. 8d , a surface of encapsulant 372 opposite interconnectstructure 382 undergoes a grinding operation with grinder 206 to reducea thickness of the encapsulant 372 similar to FIG. 6f . The grindingoperation exposes conductive layer 370, as shown in FIG. 8e .Alternatively, or in combination with grinding operation, shallow LDA isused to expose conductive layer 370 of interconnection units 364 throughencapsulant 372, as shown in FIG. 8e . In some embodiments, a chemicaletch is used to remove one or more portions of encapsulant 372. FIG. 8efurther shows a mechanical support layer 380 is formed over back surface128 and encapsulant 372 using printing, spin coating, spray coating,screen printing, stencil printing, jetting, lamination, or othersuitable process. An optional cleaning process such as a laser clean,dry plasma, or wet development may also be used. Materials of mechanicalsupport layer 380 include one or more layers of photosensitive polymerdielectric film with or without fillers, photosensitive compositeresist, non-photosensitive polymer dielectric film, LCP, laminatecompound film, insulation paste with filler, liquid molding compound,granular molding compound, polyimide, polymer flux, underfill, or othermaterial having similar insulating and structural properties. One ormore portions of mechanical support layer 380 are removed by LDA.

In FIG. 8f , an insulating or passivation layer 388 is formedconformally over and follows the contours of conductive layer 386 andinsulating layer 385. Insulating layer 388 contains one or more layersof low temperature curable polymer dielectric resist (i.e., cures atless than 260° C.) with or without filler, SiO2, Si3N4, SiON, Ta2O5,Al2O3, or other material having similar insulating and structuralproperties. Insulating layer 388 is deposited using PVD, CVD, printing,spin coating, spray coating, sintering, thermal oxidation, or othersuitable process. A portion of insulating layer 388 is removed by anexposure or development process, LDA, etching, or other suitable processto form openings 390 in the insulating layer, which expose portions ofconductive layer 386 for subsequent electrical interconnection. In someembodiments, insulating layer 388 comprises an encapsulant similar toencapsulant 372.

FIG. 8f further shows a semiconductor package, semiconductor die, orsemiconductor component 230, singulated from a semiconductor wafersimilar to FIGS. 3a-3c , is disposed over openings 390 in insulatinglayer 388. Using a pick and place operation, semiconductor die 230 ismounted over insulating layer 388 such that bumps 258 are disposedwithin openings 390 to bond with exposed portions of conductive layer386. In some embodiments, semiconductor die 230 does not have bumps 258and instead bumps are preformed within openings 390.

FIG. 8g shows semiconductor die 230 mounted over semiconductor die 124with bumps 258 disposed within vias 390 of insulating layer 388 as asemiconductor package 400. An electrically conductive bump material isdeposited over conductive layer 370 using an evaporation, electrolyticplating, electroless plating, ball drop, or screen printing process. Thebump material can be Al, Sn, Ni, Au, Ag, Pb, Bi, Cu, solder, andcombinations thereof, with an optional flux solution. For example, thebump material can be eutectic Sn/Pb, high-lead solder, or lead-freesolder. The bump material is bonded to conductive layer 370 using asuitable attachment or bonding process. In one embodiment, the bumpmaterial is reflowed by heating the material above its melting point toform balls or bumps 392. In some applications, bumps 392 are reflowed asecond time to improve electrical contact to conductive layer 370. Inone embodiment, bumps 392 are formed over a UBM having a wetting layer,barrier layer, and adhesive layer. The bumps can also be compressionbonded to conductive layer 370. Bumps 392 represent one type ofinterconnect structure that can be formed over conductive layer 370. Theinterconnect structure can also use conductive paste, stud bump, microbump, or other electrical interconnect.

Modular interconnection units 364 disposed around semiconductor die 124provide vertical interconnect with reduced RDL application.Interconnection units 364 formed along one side or in an L-shapedconfiguration around semiconductor die 124, similar to FIG. 4c , providestructural support during packaging and reduce shifting during theapplication of encapsulant 372 and external semiconductor componentssuch as semiconductor die 230. Interconnection units 364 can form aborder, frame, slot, or other similar support structure around a sideportion or portions or over a peripheral region of semiconductor die124. Interconnection units 364 increase structural support and reduceshifting of the semiconductor device 124 during encapsulation.Interconnection units 364 reduce the quantity of RDLs formed within apackage. Interconnection units 364 provide partial backside RDL withoutthe cost, time, and other manufacturing restraints associated withforming multiple RDLs in a semiconductor package. Interconnection units364 provide design flexibility while reducing z-direction packageheight. Mechanical support layer 380 is a backside protection/balancelayer that provides structural support for semiconductor package 400,balances stress on semiconductor package 400, and reduces warping orcracking of semiconductor package 400.

Bumps 258, or interconnect structures of an external device such assemiconductor die 230, can be disposed or formed on semiconductor die230 in an orientation matching the layout or orientation ofinterconnection units 364 disposed around semiconductor die 124.Matching bumps 258 or interconnect structures of semiconductor die 230with the layout of interconnection units 364 reduces manufacturingmaterials and cost. Matching interconnection units 364 with bumps 258 orinterconnect structures of semiconductor die 230 provides a consistentand reliable 3D vertical interconnect.

Creating vertical interconnect by forming interconnection units 364 asopposed to build-up layers and RDLs provides enhanced flexibility forpackaging design. Interconnection units 364 do not have to be disposedover an entire surface area and can be disposed at customized locationswithin semiconductor package 400 which is difficult to accomplish withother interconnect structures. For example, disposing interconnectionunits 364 over first side portions of the semiconductor die 124 and notaround second side portions of the semiconductor die 124 can freevaluable space within semiconductor package 400 and expose the secondside portions around semiconductor die 124 for additional electricalcomponents. Alternatively, where increased vertical interconnect densityis desired, interconnection units 364 can completely surroundsemiconductor die 124 for a dense yet flexible vertical interconnect.Interconnection units 364 help to conserve materials and also optimizethe space within semiconductor package 400.

While one or more embodiments of the present invention have beenillustrated in detail, the skilled artisan will appreciate thatmodifications and adaptations to those embodiments may be made withoutdeparting from the scope of the present invention as set forth in thefollowing claims.

What is claimed:
 1. A method of making a semiconductor device,comprising: providing a first semiconductor die; disposing a modularinterconnect unit adjacent to the first semiconductor die; forming abuild-up interconnect structure over the first semiconductor die andmodular interconnect unit; and disposing a second semiconductor die overthe modular interconnect unit and a non-active surface of the firstsemiconductor die, wherein the second semiconductor die is coupled tothe build-up interconnect structure through the modular interconnectunit.
 2. The method of claim 1, further including: depositing anencapsulant over the first semiconductor die and modular interconnectunit; and forming the build-up interconnect structure over theencapsulant.
 3. The method of claim 2, further including: forming anopening in the encapsulant over the modular interconnect unit; andcoupling the second semiconductor die to the modular interconnect unitthrough the opening.
 4. The method of claim 1, further includingproviding an underfill dot between the first semiconductor die andsecond semiconductor die.
 5. The method of claim 1, wherein the firstsemiconductor die extends outside a footprint of the secondsemiconductor die opposite the modular interconnect unit.
 6. The methodof claim 1, wherein the modular interconnect unit includes an ‘L’ shape.7. A method of making a semiconductor device, comprising: providing asemiconductor die; disposing a modular interconnect unit adjacent to thesemiconductor die; and disposing a semiconductor component over themodular interconnect unit and a non-active surface of the semiconductordie.
 8. The method of claim 7, further including providing an underfilldot between the semiconductor die and semiconductor component.
 9. Themethod of claim 7, further including: disposing the semiconductor dieand modular interconnect unit on a carrier; and depositing anencapsulant over the carrier, semiconductor die, and modularinterconnect unit.
 10. The method of claim 9, further including forminga build-up interconnect structure over the semiconductor die, modularinterconnect unit, and encapsulant.
 11. The method of claim 10, whereinthe semiconductor component is coupled to the build-up interconnectstructure through the modular interconnect unit.
 12. The method of claim7, wherein the semiconductor die extends outside a footprint of thesemiconductor component.
 13. The method of claim 7, further includingforming: forming an insulating layer over the semiconductor die; anddisposing the semiconductor component over the semiconductor die andmodular interconnect unit with the insulating layer supporting thesemiconductor component.
 14. A semiconductor device, comprising: a firstsemiconductor die; a modular interconnect unit disposed adjacent to thefirst semiconductor die; a build-up interconnect structure formed overthe first semiconductor die and modular interconnect unit; and a secondsemiconductor die disposed over the modular interconnect unit and anon-active surface of the first semiconductor die, wherein the secondsemiconductor die is coupled to the build-up interconnect structurethrough the modular interconnect unit.
 15. The semiconductor device ofclaim 14, further including an encapsulant deposited over the firstsemiconductor die and modular interconnect unit.
 16. The semiconductordevice of claim 15, further including an opening formed in theencapsulant over the modular interconnect unit, wherein the secondsemiconductor die is coupled to the modular interconnect unit throughthe opening.
 17. The semiconductor device of claim 14, further includingan underfill dot disposed between the first semiconductor die and secondsemiconductor die.
 18. The semiconductor device of claim 14, wherein thefirst semiconductor die extends outside a footprint of the secondsemiconductor die.
 19. The semiconductor device of claim 14, wherein themodular interconnect unit includes an ‘L’ shape.
 20. A semiconductordevice, comprising: a semiconductor die; a modular interconnect unit;and a semiconductor component disposed over the modular interconnectunit and semiconductor die.
 21. The semiconductor device of claim 20,further including an underfill dot disposed between the semiconductordie and semiconductor component.
 22. The semiconductor device of claim20, further including an encapsulant disposed over the semiconductor dieand modular interconnect unit.
 23. The semiconductor device of claim 22,further including a build-up interconnect structure formed over thesemiconductor die, modular interconnect unit, and encapsulant.
 24. Thesemiconductor device of claim 23, wherein the semiconductor die iscoupled to the build-up interconnect structure through the modularinterconnect unit.
 25. The semiconductor device of claim 20, wherein thesemiconductor die extends outside a footprint of the semiconductorcomponent.